Milking of cows on a large scale is almost entirely done with a milking machine. The milking machine draws the milk from the cow's udder by pulsating vacuum, e.g., by attaching a teat cup connected to a vacuum pump and pulsating the vacuum to alternately allow the milk to fill and drain from the area of the udder and teat to simulate hand milking of the cow. The tendency is to minimize the milking time by using high vacuum which can cause irritation or damage to the teat and udder.
The damage to tissue caused by the milking machine followed by exposure of the damaged tissue to certain microorganisms can result in an infection known as mastitis. Control of mastitis is of great economic importance to dairy farmers because an infected cow's contaminated milk cannot be marketed. The udder and teats of an infected cow can be treated with an antibiotic to inhibit the growth of mastitis once it has begun. However, the milk from such cows cannot be sold until the antibiotic is absent from the milk (usually about 3-5 days after the last treatment).
According to experts, prevention of mastitis by the dipping of teats in an antimicrobial (biostatic or biocidal) solution after mixing is one of the most effective procedures that a dairy farmer can follow. An essential function of a teat dip is to prevent mastitis by killing or controlling infectious microorganisms. The teat dip product desirably has a wide spectrum of antibacterial activity (i.e., it can kill or inhibit the growth of a wide variety of mastitis-causing microorganisms), and has emollient properties to prevent irritation of the skin on which it is applied.